diff options
author | Li Zefan <lizf@cn.fujitsu.com> | 2009-06-23 21:54:54 -0400 |
---|---|---|
committer | Ingo Molnar <mingo@elte.hu> | 2009-06-24 05:02:53 -0400 |
commit | d82d62444f87e5993af2fa82ed636b2206e052ea (patch) | |
tree | 701f28de7def6c58d80db72a462171cab013b514 | |
parent | 694ce0a544fba37a60025a6803ee6265be8a2a22 (diff) |
ftrace: Fix t_hash_start()
When the output of set_ftrace_filter is larger than PAGE_SIZE,
t_hash_start() will be called the 2nd time, and then we start
from the head of a hlist, which is wrong and causes some entries
to be outputed twice.
The worse is, if the hlist is large enough, reading set_ftrace_filter
won't stop but in a dead loop.
Reviewed-by: Liming Wang <liming.wang@windriver.com>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <4A41876E.2060407@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
-rw-r--r-- | kernel/trace/ftrace.c | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index dc810208edde..71a52c172140 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c | |||
@@ -1417,10 +1417,20 @@ static void *t_hash_start(struct seq_file *m, loff_t *pos) | |||
1417 | { | 1417 | { |
1418 | struct ftrace_iterator *iter = m->private; | 1418 | struct ftrace_iterator *iter = m->private; |
1419 | void *p = NULL; | 1419 | void *p = NULL; |
1420 | loff_t l; | ||
1421 | |||
1422 | if (!(iter->flags & FTRACE_ITER_HASH)) | ||
1423 | *pos = 0; | ||
1420 | 1424 | ||
1421 | iter->flags |= FTRACE_ITER_HASH; | 1425 | iter->flags |= FTRACE_ITER_HASH; |
1422 | 1426 | ||
1423 | return t_hash_next(m, p, pos); | 1427 | iter->hidx = 0; |
1428 | for (l = 0; l <= *pos; ) { | ||
1429 | p = t_hash_next(m, p, &l); | ||
1430 | if (!p) | ||
1431 | break; | ||
1432 | } | ||
1433 | return p; | ||
1424 | } | 1434 | } |
1425 | 1435 | ||
1426 | static int t_hash_show(struct seq_file *m, void *v) | 1436 | static int t_hash_show(struct seq_file *m, void *v) |